Aircraft and the control thereof



Jan. 5, 1937. F. M. TRUMAN 2,066,375

AIRCRAFT AND THE CONTROL 'fHEREOF Filed April 15, 1933 7 Sheets-Sheet l I I BY M Jan. 5, 1937. F. M. TRUMAN 2,066,375

AIRCRAFT AND THE CONTROL THEREOF Filed April 15, 1933 '7 Sheets-Sheet 2 "ATTORNEYS Jan. 5, 1937. F. M. TRUMAN. 6,

AIRCRAFT AND THE CONTROL THEREOF Filed April 15, 1933 7 Sheets-Sheet 3 #9 I 30w j? v b u w 57 I. if 63 f lNVENT R A %M %W 2/ 55 BY ATTORNEYS Jan. 5, 1937.

F. M. TRUMAN AIRCRAFT AND THE CONTROL THEREOF 7 Sheets-Sheet 4 Filed April 15, 1933 INVENTOR ATTORNEYS Jan. 5, 1937; F. M. TRUMAN AIRCRAFT AND THE CONTROL THEREOF Filed April 15, 1933 7 Sheets-Sheet 5' 'lNVENT I BY Jan. 5, 1937.

F. M. TRUMAN Filed April 15, 1935 7 Sheet s-Shefc 6 ATTORNEYS Jan. '5, 1937. F. M. TRUMAN AIRCRAFT AND THE CONTROL THEREOF 7 sheets sheet 7 Filed April 15, 1933 ATTORNEYS Patented Jan. 5, 1937 UNITED STATES PATENT OFFICE AIRoRAFT AND THE coNTRL THEREOF v Fred M. Truman, Ambler, Pa.

Application April 15, 1933, Serial No. 666,378

4 Claims.

This invention relates to aircraft and the control thereof, and while certain aspects of the invention are of application in aircraft generally, the invention is particularly useful in the con- 5 trolling of heavier-than-air machines, such as aeroplanes, gliders and the like, in which there are normally provided means for controlling the craft in roll, means for controlling the craft in yaw, and means for controlling the craft in pitch, each of said means normally comprising movable control surfaces, such as ailerons, rudder and elevators, respectively.

One of the primary objects of the invention is to simplify the controls of, and especially the operations of the pilot in controlling, such an aircraft.

Another important object of the invention is the provision of supporting means for carrying certain of the movable parts of the controlling mechanism, which supporting means and controlling mechanism are so constructed and relatively arranged that the supporting means, thoughnormally fixed at a predetermined position or angular setting for a given installation, may in said given or in other installations be set at other positions or other angular relationships (especially with reference to the occupants compartment or pilots seat) as may be best suited to the convenience or preference of the operator,

control surfaces are not altered and the normal controlling actions are not interfered with.

in general, the invention contemplates broadly a common ,or unified control means or element for operating, independently or conjointly, all three controlling means of the aircraft, that is, the three means for controlling the aircraft in three different senses; and the invention further contemplates the movable mounting of the common control means in such manner that it may be actuated in three different senses, directions, or planes, either separately or conjointly, for obtaining the three controlling effects required. In carrying out this general purpose, the invention contemplates accomplishing it either by a control wheel or by a control stick, each of which as herein disclosed has certain particular advantages of its own; and the control connections may be of a rod and lever type, or of a rack and pinion or gear type, or of a lever and cable type, which respectively have specific advantages in different types or forms of aircraft.

The invention, furthermore, contemplates the attainment of one or more of the foregoing obwhile at the same time the relative control positions of the main controlling element and the jects by an arrangement in which there is a manually operable control element for a plu r-ality of control surfaces and controlling operations, which may be mounted on a movable column or formed as a movable column, or which 5 may be mounted on a fixed column, the latter being adjustable, if desired, to various fixed positions, particularly different positions of angularity, with respect to the occupants compartment or pilot's seat, as may be convenient or 10 desirable.

More specifically, the invention contemplates a vcontrol element which is rockingly tiltable, preferably longitudinally and transversely of the craft, and otherwise movable, such as by rota- 15 tion about its own axis, the invention furthermore providing different forms of mechanism to accomplish this purpose, one of which may involve the column itself being movable in said three respects, and another of which may involve a control element mounted on a fixed column in such way that the element itself is movable in said three respects. With any of such arrangements, the invention further provides for mounting the manually controllable means or I element above the floor of a cockpit or occupants compartment, as the sole element therein for effecting control movements of the craft in all three attitudes, whereas all the rest of the mechanism is removed from the cockpit or compartment or is in large part mounted below the floor thereof, where it isout of sight, out of the way, and. out of danger of undesired fouling on or contact with baggage or passengers.

vFurther objects and advantages involve provision of a control 'means which requires less space for its operation over the complete range of control movements than is common in this art; the incorporation of readily adjustable or replaceable parts such" as gears or the like for the purpose of adjusting the ratio of throw of the manual control'element to the throws of the several control surfaces; the connecticn of the control with the control surfaces in such manner that the craft always responds in the direction of instinctive movement of the control element, which is not true as to all control movements of the present ordinary aircraft especially as to the rudder; the provision of control which is readily adaptable to the use of ultimate control connections either of the push-andpull, the torque, or the tension type; the provision of a control arrangement which is readily adapted, with little change, to monoplane or 55 mechanism multiplane craft; and the provision of a common manual control element which permits hand control of. roll, yaw and pitch, simultaneously eral and in greater detail, will be evident to those skilled in the art or will appear from the following description, taken together with the accompanying drawings, in which drawings:

Figure 1 is a side elevational view of an aircraft, with parts of the craft including the lower wing omitted, illustrating one embodiment and setting of my improved controlling system;

Figure 2 is a somewhat enlarged side elevational view of the common control element for the several surfaces and of the control connections thereto, and illustrating a diil'erent setting or mounting of the control element itself with its supporting means or column:

Figure 3- is a further enlarged side elevational view of the heart of the controlling mechanism of Figures 1 and 2, with certain parts broken away and others shown in section;

Figure 3a is a side elevational view of a modiflcation of a detail of the mechanism of Figure 3;

Figure 4 is a rear elevation of the mechanism shown in Figure 3;

Figure 5 is a bottom plan view of the control wheel of the mechanism of Figures 1 to 4, with the upper end of the central connection to the wheel, which is the rudder connection, shown in section;

Figure 6 is a cross section of the control column as a whole taken on the line 6-6 of. Figure 3;

Figure 7 is a right side elevational view of the forward part of the control mechanism of Figure 1- (in other words, viewed from the side opposite to Figure 1), showing the means for carrying the control connections from beneath the floor up to the wing for aileron actuation;

Figure 8 is a fragmentary rear elevational view of the mechanism shown in Figure 7, that is, as viewed from the cockpit of the machine of Figure 1; n

Figure 9 :is a side elevational view similar to the lower portion of Figure 3, but illustrating a modified form of mechanism for transmitting the control movements from the common control element to the several surfaces, this form being particularly adapted to arrangements where the aileron control connections may pass laterally outwardly into the lower wing of a biplane type of aircraft;

Figure 10 is a front elevational view of the mechanism of Figure 9;

Figure 11 is a bottom plan view of the rudder control connections of Figure 10;

Figure 12 is a fragmentary side elevational view partly in section showing a third form of mechanism embodying the invention, .to wit: the stick, lever, and cable form of mechanism, this illustration being comparable with and taking the place of the mechanism as shown in Figure 3 or Figure 9;

Figure 13 is a front elevational view of the mechanism of Figure ,12, with certain parts omitted and others shown in section; and

Figure 14 isa top plan view'of part of the control connections to the rudder,- and with the con First form of mechanism 'with associated rudder Ii, stabilizer ll with'its appended elevators I2, and cockpit or occupant's' compartment I3, I have provided a common control element l4 (1!: this instance a wheel) which is located conveniently in front of the pilots seat II, and is mounted on a normally fixed, but preferably adjustable, column indicated in general at It.

From Figure 1 it will be evident that the only flight control protruding upwards in the cockpit above the floor I1 is the column IS with its wheel l4. The control connections themselves, indicated generally at "L19 and 20, for ailerons, rudder and elevators, respectively, are all associated with the common control element l4 by connections,

*links, levers or the like, located below said floor In this form of mechanism, as seen in Figure 2,

an aileron rock shaft or torque tube "a extends longitudinally for connection with the bottom of the control column, a pair of rudder rods l9a (one of which is behind the other inthis view) extend longitudinally for connection to the very bottom of the mechanism, and a set of elevator rods 20a also extend longitudinally to this general zone. It may be briefly pointed out here, although it will be brought out in detail later on, that each of these control means includes, at some point in its means of connection to the common control element, one or more Joint means such as indicated at 18b, Nb and 20b, so constructed and arranged as to permit, without redesigning the control connections, the location of the common control column 1 6 in difierent fixed positions, particularly different positions of angularity, such as the vertical position shown in'Flgure 1 or the tilted position shownin Figure 2, as convenience or the desire of the pilot may dictate; all without destroying or interfering with the proper operative relationships between the common control wheel 14 and the control surfaces themselves.

Turning now. to Figures 3 to 8 inclusive, which illustrate in detail the mechanism shown in gen eral assembly in Figure 1, it will be observed that the wheel is mounted at the top of the fixed column It by means of a, rudder controlling shaft 2 I, this shaft being rotatably mounted in the fixed column or support It, but held as against longitudinal, that is,- vertical movement therein, as by means of the collar devices 22 at the top and one of the conical gears 23 at the bottom, a thrust bearing 2|a being also preferably provided (Figure 4). The wheel II has a universal mounting on the upper end of said shaft or rod 2|, by means of the intersecting pivots 24 and 25, the pivot 24 being mounted to rock about the pivot 25 as an axis, and the pivot 25 being mounted to rock in the fork ends 26 of the rod 2|.

It will be observed from Figure 3 that the pivot pin 24 is inserted in a bearing block 21, carried centrally within the under side of the wheel l4, such insertion being by way of the bore 28; the bearing block 21 being held in place by means of suitable screws 29. Thus, with the wheel I 4 in its neutral position as shown in full lines in Figures 3 and 4, or with the wheel tilted in the vertical longitudinal plane of the aircraft as indicated at I 4a in Figure 3, or with the wheel tilted in a but in any of said tilting positions if the wheelbe turned about its own axis. the proper-rudder control is produced, as will be described in greater detafl hereinafter.

Before proceeding to the description of the connections between the common control means or wheel l4 and the three control surfaces, ailerons 8, rudder Ill and elevators l2, other structural details of the wheel itself (as-best seen in Figures 3, 4 and 5) should be briefly described. Recessed in the under face of the wheel, and in surrounding relation to the fixed block 21, is an annular structure, indicated in general by the reference character' 30 in Figure 5, said structure being composed of an inner ring 3011 having peripheral arms 30b, and an outer ring 30c which is formed in four segments having a more or less interlocked relation with the arms or projections 30b of the inner ring, so that a general annular frame is provided for connection to the lateral and iongitudinal controls.

This ring'or frame, as a whole, is non-rotative, and since the wheel 14 must be rotatable there must be the capability of relative rotation between said wheel and said ring structure. Although the entire ring structure including the inner ring30a and the outer ring 300 acts as a unit, the rotative mounting of the inner and outer ring parts, with relation to the wheel, may be separately provided as follows: for the irr gr ring 30a the annular shoulder portion 3| of the wheel and the conical peripheral surface 32 of the block 21 serve as a relatively rotatable mounting and as a means of retaining said ring in place; and for the outer ring structure 300 the same annular' shoulder 3| and the inner peripheral surface 33 of the wheel plus the annular retaining plate 34 serve as the rotative mounting,and the means of retaining said ring structure.

Between the inner and outer portions of the ring structure 30 are mounted four lugs 35, located in equi-spaced relation thereabout, the fore and aft lugs (seen in Figure 3) and the lateral lugs (seen in Figure 4) being apertured' at 36 (see Figure 5), to receive, respectively, the upper ends of elevator control links 31 and aileron control links 38. The lugs are further apertured, as indicated'at 39 in Figure 5, to receive the link connecting pins or pivots 40 which are seen in Figures 3 and 4.

In assembling this portion of the mechanism, the lugs 35 may be inserted inthe recesses of ring 300 (as seen in Figure 3), the segments of outer ring 300 are then brought together so that their recesses (as'also seen in Figure 3) receive the outer endsof the lugs 35, this assembly is then slipped down over the conical bearing block 21, as seen in Figure 3, the wheel I4 is slipped down over the assembly thus; formed, the annular retaining plate 34 is moved up from below into its recess as shown, the ,upper retaining ,screws- 29 are inserted from abgve, and the lower retaining screws 41 are inserted from below. The links 31 and 38 may thenbe connected to their control ring structure by inserting their pivot pins 40.

Turning now to the mounting column l6, which serves to movably mount the control wheel 14 and the various control connections, it willbe seen from Figure 6 that this column is generally cylindrical or has a central bore to receive the rudder control rod 2| which also mounts the wheel 14.

Externally of the column may be provided bear ings at spaced intervals therealong, or more preferably continuous tubes 42 (which may be formed integral with the column) to carry the elevator and aileron control rods 43 and 44 respectively, all

of said rods being longitudinally slidable in such bearings or tubes 42. It will be understood that in place of such rods 43 and 44 and the rudder rod 2|, that I may employ hollow shafts or tubes or their equivalent.

As seen in Figures 3 and 4, the upper ends of the tubular guides 42 are flared radially outwardly as at 42a so as to serve also as guides for the connecting links 31 and 38, which latter have both an endwi'se and an oscillating movement in the slotted openings 42b of the guides 42a, upon fore and aft and lateral tilting of the wheel l4, as indicated by the arrows I40 and (Z in Figure 3 and.

withthe lowermost links 46' of the elevator control system at a zone well below the floor I1; whereas the guides 42 for the aileron push-andpull control rods 44 are flared outwardly as at 42cm Figure .4, the latter guides serving to position the lower links 45 of the aileron control system. Thus the moving parts of the mechanism located above the floor l1 are for the most part housed, whereas the moving parts located farther down may be more or less open for inspection, adjustment, lubrication and repair, since such lowrgportions of the mechanism are not in position to be disturbed by the occupants in the cockpit.

For lubrication of the enclosed protected parts of the mechanism which are mainly above the floor l1 of the cockpit, I may provide lubricant apertures or channels 41, 48 and 49, in the top of the wheel l4, located respectively adjacent the universal joint device 24, and the control ring structures a: and 300. Lubrication of the rudder control shaft or column 2| within the support column 16 may be readily effected by means of a lubricant fitting 50 (see Figure 3) connecting to a bored longitudinal passage 5|, which latter may have radiating lubricant passages 52 (as seen in Figure 6) extending-out to the inner surface of the column IS. The moving control rods 43, 44 within their tubes or other bearings 42 may similarly be lubricated, or more preferably they may be lubricated from the same lubrication system as employed for the rudder control rod 2 I, as by means of lubricant channels 53, extending from the'bearing surface within the column IE to the bearing surfaces within the tubes 42. Alternatively, all of the lubrication'of all of the parts in the mounting column l6 may be ef-' fected' by the upward extension of the oilpassage 5| as indicated at 5| 0. in Figure 4, into which lubricant may drip from the universal joint device 24, 25. For such lubrication of the moving parts in the mounting column as well as for the adequate lubrication of the universal joint device, it

' is desirable that the lubricant opening 41 be made ma be inserted therethrough and directed toward the ends of the joint devices 24, 25.

Referring again to Figures 3 and 4, the lower end of the column l6 may be extended well below the floor i1, and the rudder control rod 2| may be carried on down, through fixed supporting structure 54 and 55; a pair of conical or beveled gears 23 and'23a. being mounted on the lower exten- 7 siompf the shaft 2| (gear 23 being fixed on the sha'ft" for rotation therewith and gear 23a being floating with respect to the shaft). By using two such gears 23 and two cooperating gears or pinions 56 any considerable tendency toward endthrust, or displacement of the gears or other partsrisjlabviated, and the proper and smooth differential action of the two pinions is assured, although it will be understood that the essential operation of the control could be effected by the fixed gear 23 alone.

The gears 56 are mounted on shafts 51, which are carried in a floating bearing 58 surrounding the shaft 2| and in bearings 59 which are supported on the fixed frame members 60; the latter extending from the fixed structure 54 and 55 upwardly to the floor I! where they are attached as by brackets 61. Thus a firm and rigid interbracing of the entire supporting structure is afforded.

The gears 56 carry with them a pair of spur gears 62 which mesh with racks 63, the latter being secured in links or frames 64 which are longitudinally slidable in the guideways 55 and 66, formed respectively in the fixed structure 54 and 55.

It will now be seen from Figure 4 that if the Wheel 14 be given a clockwise controlling movement (when viewed in top plan), the left hand link or frame 55 will move rearwardly and the right hand link or frame 66 will move forwardly. The resultant motions will be transmitted to the rudder ill by means of the left hand and right hand control rods or wires 13a, (Figure 3) which are respectively connected to the left and right links 84 by means of pivot pins {9b, as hereinbefore described with reference to Figures 1 and 2. Thus a clockwise turning of the control wheel, viewed in plan, will swing the rudder to the right, for use in a right turn; and a counter-clockwise turning of the wheel 14 will swing the rudder to the left, for a left turn, similar to the direction of movement of the usual steering wheel in an automobile.

The control connections from the tiltable but non-rotative ring structure 30, to the elevators, through the links 31, rods 43 and links ii, are by means of the mechanism now to be described.

The lower links 46 are connected respectively to transverse bars or rods 6'! and 88, located respectively fore and aft of the axis of the control column; these bars serving to interconnect the left and right rocking levers 69a and 69b. Said levers are rockingly mounted on short shafts 10a and 1822 which are journaled in the bifurcations 60a and 60b of the framework 60.

Gears or'pinions Ha, 1lb are mounted respectively on said shafts 19a and 10b, to move fixedly with their respective rocking levers 69a and 691). When so actuated by their levers, the lower gears Ho and lib similarly actuate the upper gears 12a. and 121); the latter gears being fixed on short shafts 13a and 1312, which are also journaled in the aforementioned bifurcated framing, and which carry at their outer ends, respectively, the rocking frames or levers 14a and 14b.

At the left hand side of the craft, the elevator control rods-or cables 20a, 20a are connected respectively to the upper and lower ends of the rocking frame 14a, by pivots indicated at 201). At the right hand side of the machine the elevator control cables 20a, 200, are similarly connected to the rocking frame or lever Mb.

As seen in Figure 1, the ultimate connection of the elevator control rods or cables 25a to the elevator I2 is by mean 0!. the control horns I211;

and the final connection of the rudder control l9a may be by means of a control horn I (la. The control movements of the rudder have been previously described. The control movements of the elevators will also be clear from the foregoing description of the several connections between the lower links 46 and the aileron control rods 20a. It is clear from Figure 3 that as the wheel I4 is tilted forwardly, as in the direction of the arrow I40, the levers 69a and 691) are moved, for example, to the position 690 (indicated in dot and dash lines) which movement through the intermediation of the gearing moves the rocking frames 14a and 14b into a position indicated in dot and dash lines at 14c. Thus the upper control members 20a to the elevators are moved rearwardly and the lower control members 20a are moved forwardly, causing the machine to nose I downwardly. The control movements of the ailerons are thus also in' accordance with the pilots instinctive reactions.

' Turning now to the connections from the wheel M, by way of the links 38, rods 44 and lower links 45, and thence to the ailerons, it will be seen that these connections are completed as follows:

The links 45 are connected to longitudinally extending bars or rods 15, one positioned at each side of the control column, by means of universal joints lBb (see Figures 2 and 4) the forward and rearward ends of the bars 15 being interconnected by transverse rocking levers 16a and 16b. The longitudinal bars and the transverse rocking levers 16a and 16b thus make a frame which is mounted on the rock shaft 180 at the rear of the control column, the latter shaft extending longitudinally and being rockingly mounted or journaled in suitable support means Tl; while in front of the control column the said frame is mounted on the rock shaft i811, which is similarly journaled in support means Ila.

The frame, composed of bars I5 and fore and aft transverse rocking levers'lia. and 16b, therefore may rock in a transverse vertical plane, and transmit the rocking motion to the central longitudinal rock shafts 18a and I80, either of which shafts may be used for making connection to the ailerons, although in the embodiment shown in Figure 1 the forward shaft |8a is used for this purpose. It will readily be seen from Figure 4 that arocking or tilting of the control wheel I to the left, as indicated by the arrow He, will tilt the rock levers 16a and 16b to the position indicated in dot and dash lines at 160, which effects a similar rocking movement of the forwardly extending rock shaft 18a. Tilting movement of the wheel in the direction of the arrow Hf effects an opposite rocking of said shaft.

By reference to Figure 1, and more especially to the details shown in Figures 7 and 8, it will be seen that the rocking movements of shaft i811 are transmitted from a plane below the floor I! up to the plane of the wing (in the type of machine illustrated) by a lower system of. levers or frames which rock in vertical planes transverse the aircraft, an upper system of levers or frames which rock in vertical planes lying longitudinally of the craft, and interconnecting links or rods. In Figure 7 is seen a lower frame comprising two levers 18 mounted fast on the shaft 18a and two interconnecting members or bars 19a and 19b. A rod a is connected at its lower end to bar 19a and at its upper end to a bar Bla of an upper rocking frame; while a second rod 80b is connccted at its lower end to the bar 191) and at its 2,066,875 upper end to a bar 821; of a second upper frame.

The first mentioned upper frame (that is, the frame having a bar 8Ia) iscompleted by a bar 8Ib and two rocking levers 83. The secondmentioned upper frame,-having the bar 82a, is completed by the bar 82b and two rocking levers 84.

Turning now tothe second lower control frame, it will be seen from Figure 7 that this comprises two rocking levers 85, interconnected at their ends by the bars 86a. and 86b, and mounted to completed by the rod 88b, which is connected at its lower 'end to the bar 88a and at its upper endto the bar 8211 of the first mentioned upper frame.

It will now be seen that the rockinglevers I8 of the first lower frame will, through the rods 88a and 88b, rock the levers 83 and 84 of the two upper frames, in opposite senses and thus turn the two upper shafts 98 and 89 in opposite directions, since the two upper frames are respectively fixed one on each of said shafts. The further interconnection of the two upper rocking frames or assemblies through the intermediation of the rods 88a and 88b and the floating lower frame or lever assembly 85 supplies simply a secondary operating interconnection between the two aileron actuating shafts 89- and 98, which makes possible the substitution of tension cables only in place of the push-and-pullrods, if desired; or if the rods are used (as shown) this secondary operating interconnection simply assures the proper operation of both ailerons, even if one or the other of the main actuating rods 88a, 8812 should break.

Referring more particularly to Figure 8, it will be seen that the aileron rods 89 and 98 are mounted for free, and reverse, rocking movements in the fixed mounting tube or flange 9I. The shaft 89 is connected as at 92 to a torque tube 93 which extends out through the left wing of the aircraft,

where its ultimate connection to the left aileron 8- is accomplished by means of a frame 94, upper and lower rods or cables 95, 96, and the usual control horns 91. A similar connection is made to the aileron on the right wing, by means of a torque tube 98 which is connected with the shaft 98 as by bolts indicated at 99; the connections to the right aileron being not shown as they are similar to the connections previously described.

By following out the connections. between the wheel I4 (Figure 4) and the left aileron 8 it will be seen that tilting the wheel to the left, as indicated by the arrow He will raise the left aileron 8 and thus tend to depress the left wing. At the same time, the right hand aileron is moved in the opposite sense, and the usual control in roll is effected; the tilting of the wheel in the direction of desired lateral inclination being in accordance with instinctive reaction. Similarly, the opposite effect is produced by tilting the wheel in the direction of the arrow I41 of Figure 4.

In the form of mechanism just described it will be observed that the control connections and the operating mechanism therefor are so constructed, positioned and arranged that the control column may be mounted at various fixed positions of adjustment. For example, as seen in Figure 2, the column I6 may be mounted in a tilted position if desired. In such event, the

angularity between the control column and its associated parts on the onehand and the leads or connections going to the rudder, elevatorsand ailerons on the other hand, is accommodated by .the universal joint connections I8b of the links 48 to their shafts I5, the pivotal connections I9b of the rods I9a with their operating frames 64,

and the pivotal connections 28b of the rods 28a with their rocking levers 14a, etc.; and if desired the length of theseveral control rods may be made readily adjustable as by means of adjustment devices I48.

To secure the column I6 in various angular mounting positions, I may employ the mounting bracket I49 (shown in Figure 2) having a plurality of apertures I58, through certain of which bolts or other securing devices I5I are inserted, the, location of these bolts being dependent upon the angle at which the column I8 is to bemounted.

The mechanism further lends itself very readily to any desired changes in the ratio between .the movements of the control element or wheel I4 and the movements of the control surfaces themselves. For example, in Figure 3a, I have illustrated a substitute pair of gears II and I2, which may be mounted on the shafts 18a and 13a in place of the gears' Ila and -Illaof Figure 3. By this means; the throw or movement of the'ailerons resulting from a given throw or tilting movement of the control. wheel may be readily adjusted. It will be understood that similar gear changes may be made, or difl'erent lengths of levers may be employed, for modifying the action of the rudder and ailerons.

Second form of mechanism In the second general form of mechanism for carrying out my invention, as illustrated in Figures 9 to 11 inclusive, I am enabled to dispense with thelower push-a'nd-pull links (such as used in-Figures 3 and 4), eliminate a number of levers, readily employ ball bearings for the various shafts, and render that portion of the mechanism which is below the floor much more compact in form.

In this form of mechanism, the main column I6a may be of plane tubular form, housing the rudder controlling shaft I88,the said tube being externally formed with four slots I8I serving as guideways for the sliding control rods I82 for- These the elevators and I83 for the ailerons. rods are continued down beneath the floor in the form of racks I82a, Wild.

The rudder operating shaft I88 may be keyed at the bottom to a gear I84, the said shaft and gear beingmounted in suitable ball bearings.

to which the ruddercontrofiods I9a are con-- nected by pivots I b.

For the elevatorwontrol, the racks I 82a engage gears III, which are fast on shafts IIZ, each such shaft carrying a pair of levers H3, H4; the levers 3, on the left side of the craft being connected in tandem by links I I5, and the levers II4 on the right side of the craft being connected in tandem by similarlinks 8., At

the left side of the craft, an upper elevator rod 28a and a lower elevator rod 28a are respectively connected to the upper and lower ends of the rearmost lever Ill. or they may be formed as direct continuations of the links I I5, as shown in Figure 9. A similar pair of rods 20a is connected at the right side of the craft to the levers II4 or to their connecting links II6.

For operation of the ailerons, the racks I03ct engage gears I I1, which are respectively fixedly mounted on shafts II8. These shafts extend in a fore and aft direction and fixedly carry at their extreme ends the pinions H9 which engage gears I20, the rear gear I20 (in Figure 9) being mounted on a shaft I2I and the forward gear I20 being mounted on a shaft I22. these shafts thus correspond respectively to shafts I and la of Figure 3, and the connection to the ailerons may be taken from either of these shafts.

As illustrated, the aileron connection is taken from the shaft I22, by means of a depending arm or lever I23, and in this instance it is located beneath the floor I1 in a position approximately on a level with the wing of a low wing monoplane, or with the lower wing of a biplane, and the lateral connection to the ailerons'nray be made by means of a rod I24, extending out through the wings; although it should be understood that the mechanism shown in Figures '1 and 8 could readily be associated with the shaft I22, for actuation thereby.

Third form of mechanism Turning now to the third form of mechanism embodying the invention, as illustrated in Figures 12 to 14 inclusive, it will be seen that this is of an extremely light and simple type, being well adapted for use in small aeroplanes or in light weight gliders. Here the control column I25 is itself made movable in three senses, to'wit: it

may be turned about its own axis for actuating the rudder, it may be moved forwardly and rearwardly in the plane of the arrow I25a (Figure 12) for actuating the elevators, and it may be actuated laterally in a transverse plane, as indicated by the arrows I25b (Figure 13) for actuating the ailerons.

Instead of a wheel, the column I25 is provided with a bar or handle I26, preferably provided with convenient and comfortable hand grips I21. The column or stick I25 is the only part of the mechanism which projects above the floor I1. It is mounted by a universal joint in a rudder bar I26. As seen in Figure 14 the stick I25 is secured in a socket I29, carried by transverse pivot pins I30 in a yoke I3I the latter being pivoted on longitudinal pivots I32 in the rudder bar itself.

The stick is thus capable of tilting in any direction, without disturbing the position of the rudder bar I26, but if turned about its own axis (either when upright or when in any position of tilt) it turns'the rudder bar in the plane of the arrows I28a. The bar itself is in turn definitely located and positioned by means of the circular grooves or peripheral recesses I20b, into which are fitted the supporting and positioning brackets I 33 which are secured fast on the bottom of the floor I1.

This'assembly serves also to mount the center of the universal joint of the stick at a fixed point.

It will be observed that the connections from the rudder bar I28 to the rudder will produce, for a given bar movement, a rudder movement which is diametrically opposite tothe rudder movement normally produced with the ordinary foot operated rudder bar or rudder'pedals of the usual aeroplane control system. This effect is accomplished by hooking the rudder control cables IS on to the front of the rudder bar as by'means of the apertured lugs I39, and then passing said cables forwardly, thence around pulleys I40, and finally rearwardly to the rudder. The result of this arrangement is that the control bar I26 with its hand grips I21 is turned, just as wheel I4 of the previously described constructions would be turned, in the direction in which it is desired to turn the machine. This is the direction in which the steering bar of an ordinary sled is turned for steering, and is the instinctive direction for operating the control bar I26 of the control stick.

For the control of the elevators, it will be observed that the lower end of the control column or stick slidably engages a slot I34 in a U-shaped yoke I35, the said yoke lying in a transverse plane and having its upright legs I36 (only one of which is shown) mounted on pivot pins I31 which are supported'in brackets I36, the axis line of the pivots I31 being positioned to intersect the center of the universal joint which mounts the control stick. By this arrangement, longitudinal movement of the stick as seen in Figure 12 swings the yoke I35 fore and aft about the axis I31 which is concentric to thelongitudinal pivot axis of the stick, and this effect will be produced regardless of the lateral tilting position of the stick.

The connections from the yoke I 35 to the elevators are, as in the case of the rudder, made by means of cables. The cables 20' are connected to the yoke I35 by fore and aft lugs I H, there being right and left lugs for the right and left elevators, as seen in Figure 13. In order to get the proper elevator movements, each cable 20' connected to the forward lug I is passed over a pulley I42 and thence rearwardly to the lower control horn of the elevator.

'Turning now to the control of the ailerons, it

will be seen that this is very similar to the control for the elevators. Intermediate the universal joint of the stick and the lower end of the stick, the stick is slidably engaged in a slot I43 of a longitudinally extending yoke I44, the upright legs I45, of which are mounted on pivot pins I46 which are supported in brackets I41, the axis line of these pins being in longitudinal alignment with the pivot.l32 of the universal joint for the stick. Thus, regardless of the longitudinal tilting position ofthe stick I25, lateral movements-of the stick in the directions of the arrows I25b will suitably rock the yoke I44 and thence the pivots I46. v

Either pivot I46 may be extended for suitable connection to the ailerons, and in this case the it upwardly when the stick I25 was tilted toward the right. To complete the system it is only necessary that the lower control horns of the right ,and left ailerons be interconnected by a cable passing forwardly from each aileron and then transversely across the machine. Such cable interconnection between right and left ailerons is known and need not be further described or' shown in detail.

General summary as to all forms of the mechanism From the detailed description of the several forms of mechanism, it will be evident that the general objects and advantages stated in the fore part-of the specification are attained by any of the illustrated forms of construction, and cspecially that the invention provides a unified control system which is easier to operate than those heretofore in use; that the actual throws of the various control surfaces with respect to the several movements of the control member are readily adjustable; that the control surfaces are in all instances and under all circumstances so connected upand actuated by the common control that the craft responds to the direction ap-' plied at the control element itself; that the mechanism requires only the hands to operate it, thus allowing the feet to operate the brakes when landing or to operate any other controls that may be operated by them at any time; that the mechanism is easy to assemble; and that the cabin or cockpit is freed of a number of moving parts as compared with ordinary practice.

Summary of specific advantages of first form In addition to the general advantages, the first form of mechanism obviously has decided advantages in that most of the moving parts,

above the floor, are encased in a stationary housing; thus further that less space is required to operate the control through its complete range of throw; that the location of the control element is readily adjustable, and this without interference with or substantial modification of the control connections; and that a novel and convenient form of lubricating the enclosed moving parts is provided.

Summary of specific advantages of second form Some of the particular advantages of the sec- Summary of specific advantages of third form Specifically, this form of the mechanism involves the advantages that parts similar to the usual stick and rudder bar can be employed and yet the rudder bar need not be operated by the feet, and is in fact located out of the way beneath the floor; that the hand bar on the stick is moved in the instinctive direction for control either right or left, in place of the common arrangement on aircraft, which is difficult to become accustomed to; that this is the simplest, lightest in weight, least expensive, and easiest to install, of the three forms; and that all the connections are made to all the control surfaces by means of light tension cables; rods, gears and certain other moving parts being eliminated.

However, as to the use of tension cables, it should be observed that they may also be substituted in the first and second forms of mechanism, in place of the rods and torque tubes there shown, although the said rods and tubes are peculiarly adapted to large machines with heavy operating loads. V t v I claim:--- v I t 1. An aircraft control assembly, adapted to be coupled to ailerons, elevator and rudder, comprising a control stick tiltable in all directions and having operating means coupling it with the ailerons and elevator, at rudder bar, a universal joint for so tiltably mounting the control stick upon the rudder bar and constructed to transmit rotation of the stick upon itsown axis to said bar, and an external annular groove on the rudder bar, with a fixed supportengaging said groove to provide for oscillation d the rudder bar in its horizontal plane and to fix the said bar and thus the control stick as against bodily horizontal and vertical displacement. I

2. An aircraft control system comprising, in combination with the ailerons, elevator and rudder, a normally upright control column, a generally horizontal rudder bar, means pivotally mounting said rudder bar intermediate its ends for rotative movement in its horizontal plane and cooperating therewith to restrain movements in other planes, an upright aperture through said rudder bar through which said column extends, a universal. joint mounting and securing said column to said rudder bar comprising a ring pivotally mounted in said aperture on ahorizontal axis lying in the plane of the bar, and pivotally carryingsaid column on a horizontal axis at right angles to that first mentioned, a yoke pivotally suspended from an axis aligned with the first mentioned axis of the universal joint, a second yoke pivotally suspended from an axis aligned with the second mentioned axis of the universal joint, means of sliding engagement between said column and said yokes, whereby each of said yokes and said rudder bar can be independently and conjointly operated by movements of said column, and operating connections from the ailerons to one of said yokes, from the elevator to the other of said yokes, and from the rudderto said bar.

3. An aircraft control system comprising, in

combination with the ailerons, elevator and rud-' I der, a normally upright control column, a generally horizontal rudder bar, means pivotally mounting said rudder bar intermediate its ends for rotative movement in its horizontal plane and cooperating therewith to restrain movements in other planes, an upright aperture through said rudder bar through which said column extends, a universal joint mounting and securing said column to said rudder bar comprising a ring pivotally mounted in said aperture on a horizontalaxis lying in the plane of the bar and pivotally carrying said column on a horizontal axis at right angles to that first mentioned, a yoke pivotally suspended from an axis aligned withthe first mentioned axis of the universal joint, a second yoke pivotally suspended from an axis aligned with the second mentioned axis of the universal joint, means of sliding engagement between said column and said yokes, whereby each of said yokes and said rudder bar can be independently and conjointly operated by movements of said column, and operating connections from the ailerons to one of said yokes, from the elevator to the other of said yokes, and from the rud-.

der to said bar, the aileron connections being coupled to produce lateral tilting of the craft corresponding to lateral tilting of the column on its universal joint, the elevator connections being erally horizontal rudder bar, means pivotally mounting said rudder bar intermediate its ends for rotative movement in its horizontal plane and cooperating therewith to restrain movements in other planes, an upright aperture through said rudder bar through whichflsaid column extends,

a universal joint mounting and securing said column to said rudder bar comprising a ring pivotally mounted'in said aperture on a horizontal axis lying in the plane of the bar and pivotally carrying said'column on a horizontal axis at right angles to that first mentioned, a yoke pivotally suspended from an axis aligned with the first mentioned axis of the universal joint, a second yoke pivotally suspended from an 9 axis aligned with the second mentioned axis of of said yokes and said rudder car can be indethe universal joint, means of sliding engagement between said column and said yolres, whereby each aoeas're turning of the craft to correspond to the direc-.

tion of rotation of the column about its own axis and comprising rudder cables extending forwardly from said bar and thence around sup porting devices rearwardly to the rudder.

, FRED M. TRUMAN. 

